Buggy code:
public ImportDeclaration convertImport ( ImportReference importReference ) { } public TypeDeclaration convert ( org . eclipse . jdt . internal . compiler . ast . TypeDeclaration typeDeclaration ) { } private void buildBodyDeclarations ( org . eclipse . jdt . internal . compiler . ast . TypeDeclaration typeDeclaration , TypeDeclaration typeDecl ) { } private void checkAndAddMultipleFieldDeclaration ( FieldDeclaration [ ] fields , int index , List bodyDeclarations ) { } private void checkAndAddMultipleLocalDeclaration ( Statement [ ] stmts , int index , List blockStatements ) { } public Name convert ( TypeReference typeReference ) { } public SimpleName convert ( SingleNameReference nameReference ) { } public Name convert ( QualifiedNameReference nameReference ) { } private QualifiedName setQualifiedNameNameAndSourceRanges ( char [ ] [ ] typeName , long [ ] positions , AstNode node ) { } public Expression convert ( ThisReference reference ) { } public ThisExpression convert ( QualifiedThisReference reference ) { } public Name convert ( QualifiedSuperReference reference ) { } public ArrayAccess convert ( ArrayReference reference ) { } public Expression convert ( FieldReference reference ) { } public Expression convert ( Reference reference ) { } public Name convert ( NameReference reference ) { } public TypeDeclaration convert ( MemberTypeDeclaration typeDeclaration ) { } public Type convertType ( TypeReference typeReference ) { } public MethodDeclaration convert ( AbstractMethodDeclaration methodDeclaration ) { } public Expression convert ( org . eclipse . jdt . internal . compiler . ast . Expression expression ) { } public ParenthesizedExpression convertToParenthesizedExpression ( org . eclipse . jdt . internal . compiler . ast . Expression expression ) { } public ClassInstanceCreation convert ( AllocationExpression expression ) { } public ClassInstanceCreation convert ( AnonymousLocalTypeDeclaration expression ) { } private void buildBodyDeclarations ( AnonymousLocalTypeDeclaration expression , AnonymousClassDeclaration anonymousClassDeclaration ) { } public ArrayCreation convert ( ArrayAllocationExpression expression ) { } public SingleVariableDeclaration convert ( Argument argument ) { } public ArrayInitializer convert ( org . eclipse . jdt . internal . compiler . ast . ArrayInitializer expression ) { } public Expression convert ( QualifiedAllocationExpression expression ) { } public Assignment convert ( org . eclipse . jdt . internal . compiler . ast . Assignment expression ) { } public Assignment convert ( CompoundAssignment expression ) { } public PrefixExpression convert ( org . eclipse . jdt . internal . compiler . ast . PrefixExpression expression ) { } public PostfixExpression convert ( org . eclipse . jdt . internal . compiler . ast . PostfixExpression expression ) { } public CastExpression convert ( org . eclipse . jdt . internal . compiler . ast . CastExpression expression ) { } public Type convertToType ( NameReference reference ) { } public Expression convert ( ClassLiteralAccess expression ) { } public BooleanLiteral convert ( FalseLiteral expression ) { } public BooleanLiteral convert ( TrueLiteral expression ) { } public NullLiteral convert ( org . eclipse . jdt . internal . compiler . ast . NullLiteral expression ) { } public CharacterLiteral convert ( CharLiteral expression ) { } public NumberLiteral convert ( DoubleLiteral expression ) { } public NumberLiteral convert ( FloatLiteral expression ) { } public NumberLiteral convert ( IntLiteral expression ) { } public NumberLiteral convert ( IntLiteralMinValue expression ) { } public NumberLiteral convert ( LongLiteral expression ) { } public NumberLiteral convert ( LongLiteralMinValue expression ) { } public StringLiteral convert ( org . eclipse . jdt . internal . compiler . ast . StringLiteral expression ) { } public StringLiteral convert ( ExtendedStringLiteral expression ) { } public InfixExpression convert ( BinaryExpression expression ) { } public PrefixExpression convert ( UnaryExpression expression ) { } public InfixExpression convert ( InstanceOfExpression expression ) { } public ConditionalExpression convert ( org . eclipse . jdt . internal . compiler . ast . ConditionalExpression expression ) { } public Expression convert ( MessageSend expression ) { } public Expression convert ( AND_AND_Expression expression ) { } public Expression convert ( EqualExpression expression ) { } public Expression convert ( OR_OR_Expression expression ) { } public Statement convert ( Statement statement ) { if ( statement instanceof LocalDeclaration ) { <START_BUG> throw new IllegalArgumentException ( ( ( "Should<seq2seq4repair_space>not<seq2seq4repair_space>be<seq2seq4repair_space>reached:<seq2seq4repair_space>convert(" + ( statement . getClass ( ) ) ) + ")" ) ) ; <END_BUG> } if ( statement instanceof AssertStatement ) { return convert ( ( ( AssertStatement ) ( statement ) ) ) ; } if ( statement instanceof Block ) { return convert ( ( ( Block ) ( statement ) ) ) ; } if ( statement instanceof Break ) { return convert ( ( ( Break ) ( statement ) ) ) ; } if ( statement instanceof Continue ) { return convert ( ( ( Continue ) ( statement ) ) ) ; } if ( statement instanceof Case ) { return convert ( ( ( Case ) ( statement ) ) ) ; } if ( statement instanceof DefaultCase ) { return convert ( ( ( DefaultCase ) ( statement ) ) ) ; } if ( statement instanceof DoStatement ) { return convert ( ( ( DoStatement ) ( statement ) ) ) ; } if ( statement instanceof EmptyStatement ) { return convert ( ( ( EmptyStatement ) ( statement ) ) ) ; } if ( statement instanceof ExplicitConstructorCall ) { return convert ( ( ( ExplicitConstructorCall ) ( statement ) ) ) ; } if ( statement instanceof ForStatement ) { return convert ( ( ( ForStatement ) ( statement ) ) ) ; } if ( statement instanceof IfStatement ) { return convert ( ( ( IfStatement ) ( statement ) ) ) ; } if ( statement instanceof LabeledStatement ) { return convert ( ( ( LabeledStatement ) ( statement ) ) ) ; } if ( statement instanceof ReturnStatement ) { return convert ( ( ( ReturnStatement ) ( statement ) ) ) ; }

Fix:
return convertToVariableDeclarationStatement ( ( ( LocalDeclaration ) ( statement ) ) ) ;